Theorem pwex 3959

Description: Power set axiom expressed in class notation. Axiom 4 of [TakeutiZaring] p. 17. (Contributed by NM, 5-Aug-1993.) (Proof shortened by Andrew Salmon, 25-Jul-2011.)

Hypothesis

Ref	Expression
zfpowcl.1	⊢ 𝐴 ∈ V

Assertion

Ref	Expression
pwex	⊢ 𝒫 𝐴 ∈ V

Proof of Theorem pwex

Dummy variables 𝑥 𝑦 𝑧 are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		zfpowcl.1	. 2 ⊢ 𝐴 ∈ V
2		pweq 3389	. . 3 ⊢ (𝑧 = 𝐴 → 𝒫 𝑧 = 𝒫 𝐴)
3	2	eleq1d 2122	. 2 ⊢ (𝑧 = 𝐴 → (𝒫 𝑧 ∈ V ↔ 𝒫 𝐴 ∈ V))
4		df-pw 3388	. . 3 ⊢ 𝒫 𝑧 = {𝑦 ∣ 𝑦 ⊆ 𝑧}
5		axpow2 3956	. . . . . 6 ⊢ ∃𝑥∀𝑦(𝑦 ⊆ 𝑧 → 𝑦 ∈ 𝑥)
6	5	bm1.3ii 3905	. . . . 5 ⊢ ∃𝑥∀𝑦(𝑦 ∈ 𝑥 ↔ 𝑦 ⊆ 𝑧)
7		abeq2 2162	. . . . . 6 ⊢ (𝑥 = {𝑦 ∣ 𝑦 ⊆ 𝑧} ↔ ∀𝑦(𝑦 ∈ 𝑥 ↔ 𝑦 ⊆ 𝑧))
8	7	exbii 1512	. . . . 5 ⊢ (∃𝑥 𝑥 = {𝑦 ∣ 𝑦 ⊆ 𝑧} ↔ ∃𝑥∀𝑦(𝑦 ∈ 𝑥 ↔ 𝑦 ⊆ 𝑧))
9	6, 8	mpbir 138	. . . 4 ⊢ ∃𝑥 𝑥 = {𝑦 ∣ 𝑦 ⊆ 𝑧}
10	9	issetri 2581	. . 3 ⊢ {𝑦 ∣ 𝑦 ⊆ 𝑧} ∈ V
11	4, 10	eqeltri 2126	. 2 ⊢ 𝒫 𝑧 ∈ V
12	1, 3, 11	vtocl 2625	1 ⊢ 𝒫 𝐴 ∈ V

Syntax hints:   ↔ wb 102  ∀wal 1257   = wceq 1259  ∃wex 1397   ∈ wcel 1409  {cab 2042  Vcvv 2574   ⊆ wss 2944  𝒫 cpw 3386

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-11 1413  ax-4 1416  ax-14 1421  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038  ax-sep 3902  ax-pow 3954

This theorem depends on definitions:  df-bi 114  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-clel 2052  df-v 2576  df-in 2951  df-ss 2958  df-pw 3388

This theorem is referenced by:  pwexg  3960  p0ex  3966  pp0ex  3967  ord3ex  3968  abexssex  5779  npex  6628  axcnex  6992  pnfxr  8792  mnfxr  8794  ixxex  8868